Erbil resident Omar Ali, the Iraq director for the British charity Human Appeal, described scenes in the city shortly after the tremors began.

"Just survived an earthquake. Building violently shaking. Ran from 19th floor. Many tears here. Thank God, alive and out safely!" he wrote on Twitter, describing how he came across an elderly woman inside his apartment block who pleaded with him for help.

"Incredibly scary tbh (to be honest) from the 19th floor. Ran down with an old Iraqi lady ... she said don't leave me. First proper #earthquake experience."

Within hours, Ali, a British Palestinian, was back to work helping Human Appeal organise its response to the earthquake.

In neighbouring Iran, images emerged of greater devastation with rubble strewing the streets and buildings visibly damaged by the disaster.

A Twitter user named Ibrahim posted images sent to him by a relative showing the devastation in Kermanshah province, on the border with Iraq.

"People in Qasri Shirin have been buried under after the earthquake!! Electricity is gone people are outside in panic, trying to find their families," he wrote.

As the scale of the damage became clear, attention shifted to helping those in need. Some Twitter users queried what they could do, while others shared images of the outpouring of help people in Iran and Iraq were offering.

Iranian citizens in Tehran lining up to donate blood for those who wounded in last night earthquake, west of the country. pic.twitter.com/swpaqK2Aj6